This invention relates to a bacteriostatic composition for salmonellae containing, as the active ingredient, a component originating in the fermented broth of a lactic acid bacterium. More specifically, the invention relates to a composition utilizable as a feed additive, or a medicine or a health food for prophylaxis or treatment a of salmonellosis.
Some of animals are infected with salmonella when they are infants shortly after their birth, or even after they have grown to adults, due to change of the environment, etc. For preventing this, prophylaxis by administration of antibiotics, vaccines, various viable cell agents [for example, a product obtained by growth of a strain belonging to the genus Streptococcus or Lactobacillus, competitive exclusion of salmonellae (CE agent)] or the like, mannose (a kind of sugar) aggregating pathogens and inhibiting their adhesion to the intestinal wall, or oligosaccharides, etc. as health food has been tried.
However, among these methods, antibiotics have the problems, for example that resistant strains are liable to occur, the normal bacterial flora advantageously acting on the living body is also excluded, and there is the possibility of movement and remaining of : the antibiotics in processed stock farm products (xe2x80x9cRemaining of feed additives into stock farm productsxe2x80x9d, Chikusan Handbook (Stock Raising Handbook), edited by Kentaro HIMENO et al., Kodansha Co., 1984, pp. 484-485).
Vaccines have the problems, for example that they are effective only on particular pathogens, and their effects last only for a limited period (xe2x80x9cNihon no Chikusangyoxe2x80x9d (The Livestock Industry of Japan), The Latest Data Bank Predicting the Stock Raising of Japan, Chikusan Shuppan Co., 1989, pp. 21-35).
As to various viable cell agents, some of them need storage in a cool place, they are short in storage time and expensive, and it has been necessary to administer a large amount of a viable cell agent to animals having an established intestinal bacterial flora.
Mannan oligosaccharides aggregating pathogens and inhibiting their adhesion to the intestinal wall aggregate 48% of pathogenic salmonellae and inhibiting their adhesion to the intestinal wall, but are not effective on the residual pathogenic salmonellae, and has the problem [Mikio SHIMIZU, Characteristics and Usefulness of Mannan Oligosaccharides, xe2x80x9cYokei no Tomoxe2x80x9d (Friend in chicken Raising), No. 6, 14-18 (1996)].
It is said that oligosaccharides promote the growth of bifid bacteria inhabiting the large intestine of animals and forming the intestinal bacterial flora together with other bacteria, and have a salmonellae-inhibiting effect, but they are expensive and, moreover, uncertain in the effect [for example, Tsuneo FUKADA et al., On salmonella infection-inhibiting effect of oligosaccharides in chickens, xe2x80x9cKeibyo Kenpoxe2x80x9d (Research Paper on Chicken Diseases) 31, 113-117 (1995)].
Further, these antibiotics, vaccines, various viable cell agents, and oligosaccharides such as mannan oligosaccharides aggregating pathogens and inhibiting their adhesion to the intestinal wall themselves do not contain any perfume components liked by animals, and some of them rather smell disliked by animals and are unfit as feed additives.
As stated above, prior art exerts certain action and effect on the object of salmonellae inhibition, but some of them give out a foul smell, and they themselves do not show an action to enhance animal""s taste. Therefore, when they are used for example as feed additives, it has been difficult to increase the feed intake of animals and improve their physical condition.
Thus the object of the invention lies in providing a composition having a salmonella-inhibiting effect and, in addition, can increase animal""s taste.
The present inventors have intensely studied for providing a composition capable of improving or obviating drawbacks following prior art, namely a composition which is effective for prophylaxis or treatment of salmonellae infection and can increase animal""s taste. As a result, they found that a preparation originating in fermented broth with the use of a certain bacterium belonging to lactic acid bacteria can accomplish the object and completed the invention.
Thus according to the invention is provided a bacteriostatic composition for salmonellae containing, as the active ingredient, a preparation originating in a fermented broth obtained by effecting fermentation with the use of at least one strain belonging to lactic acid bacteria selected from the group consisting of the genera Leuconostoc, Streptococcus and Streptobacterium in a sucrose-containig nutrient medium.
Further, as another embodiment, there is provided a method for prophylaxis or treatment of salmonellosis comprising administering the preparation originating in the fermented broth to a test animal in an amount effective for prophylaxis or treatment of salmonellosis.
Still further, as another embodiment, there is also provided use of the preparation originating in the fermented broth as an active ingredient for preparing a composition for prophylaxis or treatment of salmonellosis of animals.